Acquisition and use of DNA-based HLA typing data in bone marrow registries.

The increased use of DNA-based typing techniques has improved the accuracy and reliability of HLA types assigned to patients requiring an allogeneic bone marrow transplant and their potential donors, facilitating better donor selection. The benefits of this technology, which will completely replace serologic typing within the next few years, have not yet been fully exploited since the typing information obtained in the form of DNA sequence polymorphisms is presently converted to an HLA allelic type for submission to a registry. Furthermore, within the registry, the allelic type may be further converted to a serologic antigen for use in the search and match process. Because the current nomenclature system makes selection of donors who are likely to provide optimal matches difficult, it is critical that DNA-based HLA typing data be recorded by registries as sequence polymorphisms tested as positive or negative rather than interpreted HLA types and that searching and matching utilize these polymorphisms. Until this transition is complete, we will not fully utilize this powerful HLA typing technology to best serve those patients seeking unrelated donors.